The tradition in DH's family is that everyone buys everyone else a "stocking stuffer", valued between $3 and $5. After much agonizing, we've come up with 2 each, and now it's time for DD's contribution. We'd like her to do something homemade, because it's more special that way.

Requirements:
~costs between $3-5
~2 year old can help
~Is more permanent than a painting...etc. We're already giving them a framed painting of DDs as 1 of their joint gifts.
~Unique. We can't do two of the same- 1 must be intended for GMA, and 1 for GPA.
~Isn't an ornament. There's no way they could fit even 1 more.

Please help!

ETA: I have 1.5 weeks to do this, so having to go to the store, or leaving time to cure is no big deal.

For my parents I went to the dollar store and I got a couple plain white coffee mugs. I got a sharpie pen and some paint and I painted my kids thumbs and made a heart with their thumbprints and then let the kids sign their name on it and baked it in the oven to set it.